High school students seeking to put the best shine on their college applications soon will be able to choose which of their SAT scores to share with admissions officers and which to hide, the College Board said.

The new policy, starting with the class of 2010, will allow students to take the widely used college entrance exam multiple times without admissions officers seeing their less-than-stellar efforts. Now, colleges receive scores of all the times a student attempted the dreaded test, whether the results were spectacular, mediocre or worse.

"Students were telling us the ability to have more control over their scores would make the test experience more comfortable and less stressful," said Laurence Bunin, senior vice president of the SAT. "We can do that without in any way diminishing the value and integrity of the SAT."

The College Board, the nonprofit organization that owns the test, made the change at a time when some universities are placing less emphasis on standardized testing in choosing prospective freshman and as the rival ACT exam is gaining popularity. The new SAT scoring option, approved Thursday by the College Board's trustees, mimics the ACT's long-standing policy.

But some high school counselors and college admissions officials voiced concern Friday that the new rules would most help affluent students whose parents can pay for multiple SAT attempts, at $45 a sitting, as well as pricey coaching. Previously, admissions officials would know if a student took the test four, five, even six times, and might be suspicious about the role of tutoring in any improved scores.

"In every policy change, there are some winners and losers," said Barmak Nassirian, associate executive director of the American Association of Collegiate Registrars and Admissions Officers. "This creates a penalty-free way for applicants who can afford the price of the test numerous times to shop for their best scores. For those students for whom cost is not a barrier, this is a tremendously good thing."

Most students take the exam twice, once each in their junior and senior years. The College Board waives the fee for lower-income students to take it twice. Only 15 percent take the exam three or more times, and research shows that repeated test taking is unlikely to further increase a student's scores, officials said.

The SAT, which takes 3 hours and 45 minutes to complete, has three sections — math, critical reasoning and writing — and a perfect score of 2,400 requires earning an 800 on each part. Colleges typically use the test results as a uniform way to compare students who come from schools across the nation with varying grading policies and curricula. Grades, recommendations, extracurricular activities and other factors also figure into the selection process.

Under the new policy, students who take the SAT or the supplemental SAT subject exams multiple times will be able to decide whether to let colleges see one, some or all of their scores. There is no extra charge, and students must opt into the program online or on the telephone; otherwise all scores will be shared.

To ensure fairness, and to stop students from "gaming the system," the College Board ruled out allowing students to mix and match their math, reasoning and writing scores from the different times they take the test.

Historically, the New York-based SAT has been popular on the East and West coasts, while the Midwest and the South are the strongholds for the ACT, based in Iowa City, Iowa. For the class of 2007, nearly 1.5 million students took the SAT, compared with the ACT's 1.3 million.

Reactions from universities and colleges were mixed. University of California officials said the policy would have no impact on their nine undergraduate campuses — they already use only the best score of a single sitting, no matter how many times an applicant tackles the exam.

Some admissions officials thought the plan might backfire for some students. Many private colleges consider only the best subscores of the three SAT sections from an applicant's various attempts — for example, possibly a math from May and a writing score from October — and that can't be done if just one day's test is sent in.

The University of Southern California, for example, opposes the new option, said Timothy Brunold, director of undergraduate admission.

"We would prefer to see a student's entire score history, because it gives us the context of how students earned their scores," he said. By submitting the single best total from one day, the applicant "may not get the benefit" of how USC and many other universities count the best section scores, he said.

Students, however, lauded the move. Jaleel Reed, soon to be a senior at Loyola High School in Los Angeles, said he wished his graduating class of '09 could take advantage of the new SAT policy. Younger students will be delighted, he said.

"You want colleges to see your best work. So this only helps your chances," said Reed, who took the SAT this spring and plans to repeat it in the fall.